Telephone-transmitter.



No. 646,678. 4 Patented Apr. 6, 1900.

v E. E. CLEMENT.

TELEPHUNE TRANSMITTER.

(Application filgd Aug. 20, 16961,

(No Model.)

Tu: Nonms PErzRs co 6 PHOTO'LITHOM WASHINGTON. u.

'NITED STATES PATENT FF EDWVARD E. CLEMENT, OF WASHINGTON, DISTRICT OFCOLUMBIA, ASSIGN OR TO THE SUN ELECTRIC MANUFACTURING COMPANY, OF NEWJERSEY.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 646,678, dated April 3,1900.

Application filed August 20,1898. Serial No. 689,130. (No model.)-

To aZZ whom it may concern: bushing a. Screwed into and through this Beit known that I, EDWARD E. CLEMENT, a bushing is the hollowscrew-threaded stem 1) citizen of the United States, and a resident ofof a box B, which contains and forms a part IVashingtomintheDistrictofColumbia, have of the operative resistance-varying means.

5 invented a certain new and useful Improve- The box B is preferably ofmetal and has a mentin Telephone-Transmitters, of which the cover 13,centrally perforated and adj ustably following is a specification.secured to the box. On the inside face of the My invention relates tothe class of telecover is secured an electrode E with acenphone-t-ransmitters in which granular carbon tral perforationregistering with the perfora- 10 is used as the resistance-varyingmeans, and tion in the cover. Within the stem of the box has specialreference to what are known as (shown at b) is an insulating-tube 11'.Restdifferentialtransmitters. In these instruing upon the bottom of thebox, inside, is a ments more than one resistance-varying pair disk ofpaper coated with shellac, (shown atp.) is provided, the arrangementbeing such as- Resting on the paper disk is a metallic disk I5topermitadouble-branched circuitto be used, or cup e, carrying theelectrode E and prothe resistance at any given moment being devided witha cond noting-stem e, which passes creased in one branch andsimultaneously inthrough the insulating-tube b in the stem Z). creasedin the other. Within'the box 13 a cylindrical shell I)", of rub- Themain trouble heretofore experienced her or paper, is disposed,and'fitted to recip- 20 with difierent-ial or pole-changingtransmitrocate easily within this shell is an electrode ters, apart fromt-he.c0mplicati0n of the cir- E, having on its peripherya washerofyieldcuits, has been the irregularity of their pering material e whichpermits free motion of formance and their difficulty of adjustment. theelectrode, but prevents the granulated I provide a containing-box forthe electrodes, carbon g from creeping under the edges there- 2 5accurately centered within the transmitterof. I have made this Washer,as shown, of a shell and having all the operative parts in ring of plushor velvet, secured by a wrapline, thus avoiding all torsional strainsand ping of thread 'in a peripheral groove on the making the action verytrue and direct, while electrode; but any other form is contemplated theadjustment, once made, is not easily lost; by my invention.

30 My invention is fully illustrated in the ac- Rigidly secured to theelectrode E is a stem companying drawings, wherein the same let- S, ofconducting material, screw-threaded on ters refer to the same partsthroughout. its extremity and jacketed for the greater part Referring tothe drawings, Figure 1 is a secof its length. by an insulating-tube s.The tional View of the transmitter complete. Fig. stem so protectedpassesthrough the perfora- 5 2 is a sectional view on the line A B ofFig. 1, tion in the front electrode E and in the cover lookingin thedirection ofthearrow. Fig. 3 is B and through a central perforation inthe a detail view showing all the parts of the elecdiaphragm D, to whichit is firmly secured trode box or buttonseparated or opened out by meansof the nuts 41 and n, which screw on the line of their common axis. Fig.4 isa upon its extremity, one on each side of the 40 diagram ofthecircuits. diaphragm.

In the drawings, A is a shell adapted to con- Referring to Fig. 4, itwill be seen that the tain all the parts of the transmitter and toelectrodes E and E are connected to the exsupport the diaphragm D.Secured to the tremities of the primary 5 of the inductionshell by sidescrews, as shown, or in any other coil, the secondary 6 of which is toline. The 45 suitable manner, isacap A, carryingamouthmiddle or movableelectrode E is connected, 5 piece M. In practice this cap is made muchthrough the local battery 4 by wire 3, to the flatter than shown in thedrawings, where the middle point of the primary. The operation shape isexaggerated for ease of illustration. with such connection is obvious.As the The shellAhasarearWardly-extending pernormal current-flow is inopposite directions 50 forated nipple a,'provided with aninsulatingthrough the primary, the core remains ueu- 10o trala veryfavorable condition for delicacy of transmission. A change due to oneoscillation of the diaphragm and its connected electrode E causescurrent to rise in one half of the primary and simultaneously to fall inthe other half,'and as these effects are opposite the resultant actionon the secondary produces a strong rise in one direction through thewhole length of the secondary equal to the sum of the individualeffects. On the reverse oscillation the current in the secondary firstsinks to zero and then reverses to an equal degree, clean-cut reversalsthus being produced.

Many advantages i-nhere in the arrangement of the electrodes shown. Allof the three circuits issue at the back of the shell,

where in a proper socket (not shown) suitable cooperative connectionsare provided. One circuit is by way of the nipple a and shell A to thediaphragm, and thence through the stem S to the central electrode E'.The second circuit is by way of the lock-nuts b on stem Z) to box B, lid13,, and electrode E The third circuit is by the central stem or wire 6within tube 1) to disk 6 and electrode E. All the parts have a commonaxis, upon which they are centered once for all, and the box B, with allthe operative parts, may be manufactured and handled as a unitself-contained, being attached to the instrument only by the screw-stemb and the nuts 17. and n.

I do not wish to be limited to the specific details of constructionshown and described, as many of them may obviously be changed withoutaffecting the character of the invention as a whole.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is

1. In a telephone-transmitter, a shell or casing in two parts, adiaphragm clamped between the parts, an orifice in the rear part and aninsulating-bushing therein a conducting-stem adjustably supported insaid bushing and having one end accessible as a contact from the outsideof the shell, an electrode-box carried upon the stem inside of the shellor casing and independently of the bushing, fixed and movableelectrodes, in the box,

and a connection between the diaphragm and the movable electrode,substantially as described.

2. In a telephone-transmitter a shell or casing and a diaphragm, a frontand rear electrode supported rigidly but adjustablyin said casing, amovable electrode between the fixed electrodes, and a rigid connectionfrom said movable electrode through the front fixed electrode to thediaphragm, substantially as described.

3. In a telephone-transmitter a diaphragm, a metallic shell or casing,an orifice therein, an insulating-bushing in said orifice, a hollowscrew-threaded stem adjustable in said bushing, a closed metallic boxcarried by said stem, two rigid electrodes in said box, one carrieddirectly thereby, and one insulated therefrom, a movable electrodebetween the rigid electrodes, insulated from the box but bothelectrically and mechanically connected to the diaphragm, and aninsulated circuit connection passing from the insulated rigid electrodethrough the hollow stem, substantially as described.

4. In a telephone-transmitter a diaphragm, two rigid electrodes, and amovable electrode between them, a rigid connection from the movableelectrode through one of the rigid electrodes to the diaphragm, andgranular conducting material between the electrodes, substantially asdescribed.

5. In a telephonic transmitter a self-contained resistance-varyingbutton or capsule, consisting of a metallic box with a perforated coverand a hollow stem, an insulated electrode seated in the box, and havingits elec' trical connect-ion led through the stem, another electrodeperforated and fixed to the inside of the cover, a movable electrodebetween the fixed electrodes and having an insulated stem extendingthrough the perforation in the cover and its attached electrode, andgranular carbon in the box between the electrodes, substantially asdescribed.

0. In a telephone-transmitter, the combination of two relatively-centraland two relatively-lateral electrode-faces, one pair being movable andone rigid in the supportingframe, granular conducting material situatedbetween the adjacent central and lateral electrode-faces, a diaphragmand a positive connection between the two movable electrodefaces wherebythey are moved in absolute synchronism with the diaphragm and so as tosimultaneously relax the pressure on one mass of granular material andincrease it on the other mass.

In witness whereof I have hereunto set my hand this 15th day of August,A. D. 1898.

EDWARD E. CLEMENT.

In presence of WM. D. GHARKY, ROBERT OSBORNE, Jr.

